Heat exchanger tube

ABSTRACT

A heat exchanger tube which, while preventing the increased flow resistance when the medium flows, can enhance the heat radiation performance, is provided. The heat exchanger tube  1  includes an upstream side linear flow path part  4 A and a downstream side linear flow path part  4 B connecting an entrance part  2  and exist part  3  to each other and enabling the medium to flow therethrough, wherein at least one of the upstream side flow path part  4 A and downstream side flow path part  4 B includes, within the flow path of the medium, wave-shaped portions  5   a,    5   b,    5   c,    5   d  extending in the longitudinal direction of the tube and continuing with each other for guiding the medium.

TECHNICAL FIELD

The invention relates to a heat exchanger tube.

BACKGROUND ART

Conventionally, there are known heat exchanger tubes which are disclosedin the patent documents 1 and 2.

Such conventional heat exchanger tubes respectively include a tubemember the two outsides of which are formed of beads except for theentrance and exit parts thereof and the central portion of which has apartition bead and a flow path enabling a medium to flow in a U-likemanner therethrough. The path has a large number of projecting portionsprojecting inward in order to stir the flowing medium for enhancing heatradiation performance. Two tube plates having such structure areassembled together to form the tube.

RELATED DOCUMENTS Patent Documents

Patent Document 1: JP-A-H02-169127

Patent Document 2: WO 1983-04090 A1

SUMMARY OF THE INVENTION Problems that the Invention is to Solve

When a large number of projecting portions are arranged within the flowpath, although the heat radiation performance is enhanced, the flowresistance increases.

The invention aims at solving the above problem and thus it is an objectof the invention to provide a heat exchanger tube which, whilepreventing the increased flow resistance when the medium flows, canenhance the heat radiation performance.

Means for Solving the Problems

In attaining the above object, the heat exchanger tube of the inventioncomprises: an entrance part for a medium; an exit part for the medium;and, an upstream side linear flow path part and a downstream side linearflow path part connecting the entrance and exist parts to each other andenabling the medium to flow therethrough, wherein at least one of theupstream and downstream side flow path parts includes, in the flow pathof the medium, wave-shaped portions extending in the longitudinaldirection of the tube and continuing with each other for guiding themedium.

Advantages of the Invention

According to the heat exchanger tube of the invention, due to provisionof the wave-shaped portions, when the medium flows, the flow resistancecan be restricted and the stirring of the medium by the wave-shapedportions can enhance the heat radiation performance.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a section view of a heat exchanger tube according to anembodiment 1 of the invention.

FIG. 2 is a section view of a heat exchanger tube according to anembodiment 2 of the invention.

FIG. 3 is section view of the heat exchanger tube according to theembodiment 2, taken along the S3-S3 line of FIG. 2.

FIG. 4 is section view of the heat exchanger tube according to theembodiment 2, taken along the S4-S4 line of FIG. 2.

MODES FOR CARRYING OUT THE INVENTION

Description is given below specifically of the mode for carrying out theinvention with reference to the embodiments shown in the drawings.

Embodiment 1

Firstly, description is given of the whole structure of the heatexchanger tube of the embodiment 1.

As shown in FIG. 1, the heat exchanger tube 1 of the embodiment 1 isused in a water-cooling type charge air cooler for cooling thecompressed air of a charger (turbocharger or supercharger) attached toan internal combustion engine.

The heat exchanger tube 1 is produced by assembling together twohalf-divided tube plates.

The tube 1 includes an outer peripheral rib portion 1 a which projectsinward in the thickness direction (height direction) thereof along theouter periphery thereof except for the entrance part 2 and exit part 3thereof.

Also, the tube 1 includes a partition rib portion (corresponding to apartition portion) 1 b formed at the central position in the widthdirection (vertical direction in FIG. 1) of the tube 1 and extendingtoward the longitudinal direction (horizontal direction in FIG. 1) ofthe tube from between the entrance part 2 and exist part 3 disposed onone end side of the tube 1. The rib portion 1 b extends up to thevicinity of a U-turn flow path part 4C (which is described later) on theother end side of the tube 1. The rib portion 1 b separates the tube 1into two areas, that is, an upstream side linear flow path part 4A and adownstream side linear flow path part 4B.

The downstream side end of the upstream side linear flow path part 4Aand the upstream side end of the downstream side linear flow path part 4b are allowed to communicate with each other on the other end side ofthe tube 1 by the U-turn flow path part 4C.

Meanwhile, the entrance part 2 and exit part 3 are arranged side by sidein the width direction of the tube 1. A parallel circuit with thecooling water of the engine used as the medium or a portion of thecooling water of the engine introduced therein, or an independentcircuit (for example, a cooling water circuit for a charger-air-cooler)different from the cooling water of the engine are allowed to enter andleave the entrance part 2 and exit part 3 through the penetration holesthereof. The entrance part 2 is connected to the upstream side end ofthe upstream side linear flow path part 4A continuously therewith, whilethe exit part 3 is connected to the downstream side end of thedownstream side linear flow path part 4B continuously therewith.

The upstream side linear flow path part 4A includes three upstream sideflow paths 4A1, 4A2 and 4A3 respectively between the outer peripheralrib portion 1 a existing on the upper side of FIG. 1 and partition ribportion 1 b. The upstream side flow paths 4A1, 4A2 and 4A3 respectivelyinclude wave-shaped multiple projecting sections 5 a, 5 b which projectside by side inward in the thickness direction (on this side in FIG. 1)between the outer peripheral rib portion 1 a and partition rib portion 1b and are wave-formed when viewed from above the thickness direction.

Similarly, the downstream side linear flow path part 4B includes threedownstream side flow paths 4B1, 4B2 and 4B3 respectively between theouter peripheral rib portion 1 a existing on the lower side of FIG. 1and partition rib portion 1 b. The downstream side flow paths 4B1, 4B2and 4B3 respectively include wave-shaped multiple projecting portions 5c, 5 d which project side by side inward in the thickness directionbetween the outer peripheral rib portion 1 a and partition rib portion 1b and are wave-formed when viewed from above the thickness direction.

Here, the wave-shaped projecting portions 5 a, 5 b, 5 c, 5 d correspondto the wave-shaped portions of the invention.

On the other hand, the U-turn path part 4C includes multiple arc-shapedprojecting portions 6 a, 6 b which are formed inside the outerperipheral rib portion 1 a on the other end side of the tube 1, projectinward in the thickness direction and are arc-shaped when viewed fromabove the thickness direction. Here, the curvature of the arc-shapedprojecting portion 6 a is set larger than that of the arc-shapedprojecting portion 6 b.

Therefore, in the U-turn path part 4C, between the outer peripheral ribportion 1 a and the outside arc-shaped projecting portion 6 a, betweenthe outside arc-shaped projecting portion 6 a and inside arc-shapedprojecting portion 6 b, and between the inside arc-shaped projectingportion 6 b and the other end side end of the partition rib portion 1 b,there are formed a total of three U-turn flow paths 4C1, 4C2 and 4C3respectively. The curvatures of the U-turn flow paths 4C1, 4C2 and 4C3are set such that the inflow direction and outflow direction of themedium can be changed 180° from each other.

In this case, the two ends of the outside arc-shaped projecting portion6 a respectively continue with the downstream side end of thewave-shaped projecting portion 5 a and the upstream side end of thewave-shaped projecting portion 5 d. This enables the medium to flowthrough the entrance part 2, outside upstream side flow path 4A1,outside U-turn flow path 4C1, outside downstream side flow path 4B1 andexit part 3.

Also, the two ends of the inside arc-shaped projecting portion 6 brespectively continue with the downstream side end of the wave-shapedprojecting portion 5 b and the upstream side end of the wave-shapedprojecting portion 5 c. This enables the medium to flow through theentrance part 2, central upstream side flow path 4A2, central U-turnflow path 4C2, central downstream side flow path 4B2 and exit part 4,and also through the entrance part 2, inside upstream side flow path4A3, inside U-turn flow path 4C3, outside downstream side flow path 4B3and exit part 3.

Here, the upstream side end of the outside arc-shaped projecting portion6 a and the downstream side end of the wave-shaped projecting portion 5a, and the upstream side end of the inside arc-shaped projecting portion6 b and the downstream side end of the wave-shaped projecting portion 5b are connected to each other respectively by linear projecting portions7 a and 7 b which are respectively extended by a specific distancetoward upstream from the downstream side end of the partition ribportion 1 b.

Although not shown, there is further prepared a third tube plate bymolding. The third tube plate includes wave-shaped projecting portionsand arc-shaped projecting portions having the shapes and positions ofimages reflected by mirrors which are so parallel arranged upwardly ofFIG. 1 as to face FIG. 1.

Then, the tube plate having the shape of FIG. 1 and the third tube plateare assembled together. In this assembled state, the wave-shapedprojecting portions, arc-shaped projecting portions and linearprojecting portions of these tube plates are opposed to each other atthe same positions.

In this state, the wave-shaped projecting portions, arc-shapedprojecting portions, linear projecting portions, outer peripheral ribportions and partition rib portions of these tube plates are fixedtogether by brazing or the like, thereby providing the tube 1.

In the above-structured heat exchanger tube, the cooling water suppliedfrom the entrance part 2 flows meandering through the three upstreamside flow paths 4A1, 4A2 and 4A3 within the upstream side linear pathportion 4A under the control of the wave-shaped projecting portions 5 a,5 b, and flows into the U-turn flow path part 4C along the linearprojecting portions 7 a, 7 b.

In the U-turn flow path part 4C, the flow direction of the cooling wateris gradually changed 180° within the three arc-shaped U-turn flow paths4C1, 4C2 and 4C 3 along the arc-shaped projecting portions 6 a and 6 b,thereby guiding the cooling water to the three downstream side flowpaths 4B1, 4B2 and 4B3.

Thereafter, the medium advances meandering within the three wave-shapeddownstream side flow paths 4B1, 4B2 and 4B3 under the control of thewave-shaped projecting portions 5 c and 5 d, and flows out from the exitpart 3.

Thus, the cooling water, while being stirred as in conventional dimplesor the like, flows within the tube. The wave-like meandering of thecooling water can restrict an increase in the flow resistance and cansecure the heat radiation performance. Also, as described above, in theU-turn flow path part as well, the direction of the cooling water isgradually changed. This can reduce the possibility that the coolingwater can strike strongly at the end of the tube and thus can be damagedby erosion.

Meanwhile, the high-temperature compressed air flowing outside the tubepasses the tube exchanges its heat with the cooling water, whereby it iscooled. After fuel is blown into this air, the mixture thereof iscombusted in the combustion room of the engine.

As described above, the heat exchanger tube of the embodiment 1 canprovide the following effects.

That is, since the wave-shaped projecting portions 5 a, 5 b, 5 c, 5 dare formed in the upstream side and downstream side linear flow pathparts 4A and 4B, the flow resistance when the cooling water flows can berestricted, and also since the cooling water flows along the wave-shapedprojecting portions 5 a, 5 b, 5 c, 5 d, the heat radiation performancecan be enhanced.

Since the tube 1 is manufactured by assembling together the twohalf-divided tube plates, the tube 1 can be manufactured easily andinexpensively.

Also, in this case, the wave-shaped projecting portions 5 a, 5 b, 5 c, 5d of the two tube plates are arranged to provide the same positions andthe wave-shaped projecting portions 5 a, 5 b, 5 c, 5 d are continuouslyopposed to each other, thereby enabling the cooling water to meander.

Also, the ends of the arc-shaped projecting portions 6 a, 6 b of theU-turn flow path part 4C are arranged to straddle the downstream sideend of the partition rib part 1 b, thereby enabling restriction ofdisturbance of the cooling water here. That is, the cooling water isenabled to flow smoothly between the linear flow path parts (between theupstream side and downstream side linear flow path parts 4A and 4B),whereby the flow resistance can be restricted.

Embodiment 2

FIG. 2 shows a heat exchanger tube 1 of an embodiment 2. In the heatexchanger tube 1 of the embodiment 2, there are prepared two tube plateshaving the same structure of the embodiment 1.

One tube plate is inverted and combined with the other to provide thetube 1.

In this case, the mirror-reflected third tube plate of the embodiment 1is not used. Thus, the wave-shaped projecting portions 5 a, 5 b, 5 c, 5d of the upstream side and downstream side linear flow path parts 4A, 4Band the arc-shaped projecting portions 6 a, 6 b respectively formed inthe other tube are disposed as shown by broken lines in FIG. 2.

In this case, in the wave-shaped projecting portions 5 a, 5 b, 5 c, 5 dand linear projecting portions 7 a, 7 b of the two tube plates, only thepartial sections thereof are opposed to each other, whereas theremaining sections are shifted from each other in the width direction ofthe tube 1. Meanwhile, the arc-shaped projecting portions 6 a and 6 b ofthe U-turn flow path part 4C are situated at the same positions and arecontinuously opposed to each other.

That is, the wave-shaped projecting portions 5 a, 5 b and wave-shapedprojecting portions 5 c, 5 d, which are paired wave-shaped portions, arealternately arranged side by side. Thus, in the wave-shaped portions,only the partial sections of the wave-shaped projecting sections 5 a, 5b constituted of the paired wave-shaped portions (or, the wave-shapedprojecting portions 5 c, 5 d) cross each other, while only such partialsections are opposed to each other.

The remaining structures are similar to the embodiment 1.

FIG. 3 is a transverse section view taken along the S3-S3 line passingthe above-mentioned mutually shifted sections, and FIG. 4 is a sectionview taken along the S4-S4 line passing the above-mentioned mutuallyopposed sections.

As can be understood from these section shapes, unlike the prior artusing a large number of dimples, the cooling water is prevented frombeing stirred greatly.

In the heat exchanger tube 1 of the embodiment 2, since the stirring iseasier than in the embodiment 1, the heat radiation performance isenhanced. In this case, the flow resistance increases slightly whencompared with the embodiment 1.

However, since, as the two tube plates to be assembled, the same tubeplate can be used, the tube 1 can be manufactured more inexpensivelythan the embodiment 1.

Although the invention has been discussed heretofore with reference tothe above embodiments, the invention is not limited to these embodimentsbut can be changed in design or the like without departing from thesubject matter thereof.

For example, in the embodiment 1, the wave-shaped projecting portions 5a, 5 b are formed in both of the upstream side and downstream sidelinear flow path parts 4A and 4B. However, the portions may also beformed only in one of the two parts.

Also, the medium may also be guided using inner fins instead of thewave-shaped projecting portions 5 a, 5 b and arc-shaped projectingportions 6 a, 6 b. Use of the inner fins can enhance the setting freedomof the shape of the wave-shaped portions.

Also, the respective arc-shaped and wave-shaped projections areconnected to each other by the linear projecting portions 7 a and 7 bextended by a specific distance toward upstream side from the downstreamside end of the partition rib portion 2 b. However, when, instead of thelinear projecting portions 7 a and 7 b, wave-shaped projecting portionsare used to assemble together two tube plates having the same shape, thetube 1 can be manufactured more inexpensively.

Although the heat exchanger tube of the invention is used in thewater-cooled charge air cooler, this is not limitative but it can alsobe applied to other types of heat exchangers.

Here, the present application is based on JPA (JPA No. 2012-239052)filed on Dec. 30, 2012 and thus the whole thereof is used herein bycitation. Also, all references cited herein are contained herein as awhole.

DESCRIPTION OF REFERENCE NUMERALS AND SIGNS

-   1: tube (heat exchanger tube)-   1 a: outer peripheral rib part-   1 b: partition rib part (partition part)-   2: entrance part-   3: exit part-   4A: upstream side linear flow path part-   4B: downstream side linear flow path part-   4C: U-turn flow path part-   4A1, 4A2, 4A3: upstream side flow path-   4B1, 4B2, 4B3: downstream side flow path-   4C1, 4C2, 4C3: U-turn flow path-   5 a, 5 b, 5 c, 5 d: wave-shaped projecting portion-   6 a, 6 b: arc-shaped projecting portion-   7 a, 7 b: linear projecting portion

1. A heat exchanger tube comprising: an entrance part for a medium; anexit part for the medium; and an upstream side linear flow path part anda downstream side linear flow path part connecting the entrance andexist parts to each other and enabling the medium to flow therethrough,wherein: at least one of the upstream side and downstream side flow pathparts includes, within the flow path of the medium, wave-shaped portionsextending in the longitudinal direction of the tube and continuing witheach other for guiding the medium; and the medium flows flow path partsdefined by the wave-shaped portions and located next to each other. 2.The heat exchanger tube according to claim 1, wherein the wave-shapedportions are projecting portions projecting inwardly of the tube.
 3. Theheat exchanger tube according to claim 2, wherein the wave-shapedprojecting portions are inner fins.
 4. The heat exchanger tube accordingto claim 1, wherein the entrance and exit parts are arranged on one endside of the tube, the tube includes, on the other end side thereof, aU-turn flow path part for connecting the upstream side and downstreamside linear flow path parts to each other, and the U-turn path partincludes an arc-shaped projecting portion projecting inwardly of thetube and continuing with the wave-shaped portion formed at least in oneof the upstream side and downstream side linear flow path parts.
 5. Theheat exchanger tube according to claim 1, wherein the wave-shapedportion is constituted of multiple wave-shaped portions arranged in thethickness direction of the tube.
 6. The heat exchanger tube according toclaim 5, wherein a pair of the wave-shaped portions are so arranged asto be situated at the same position and such wave-shaped portions areopposed to each other continuously.
 7. The heat exchanger tube accordingto claim 5, wherein only the partial sections of the paired wave-shapedportions cross each other and only such partial sections are opposed toeach other.
 8. The heat exchanger tube according to claim 5, wherein thepaired wave-shaped portions are parallel arranged alternately.
 9. Theheat exchanger tube according to claim 4, wherein the end of a U-turnportion of the U-turn flow path part straddles inwardly the end of apartition part for separating the upstream side and downstream side flowpath parts from each other.
 10. The heat exchanger tube according toclaim 1, wherein: the medium flowing within the tube is cooling water;and the heat exchanger tube is the tube of a water-cooling type chargeair cooler for allowing the cooling water and compressed air flowingoutside the tube to exchange heat with each other to thereby cool thecompressed air.
 11. The heat exchanger tube according to claim 5,wherein phases corresponding to shapes of the wave-shaped portions,located next to each other in the thickness direction of the tube, areoffset from each other.
 12. The heat exchanger tube according to claim5, wherein phases corresponding to shapes of the wave-shaped portions,located next to each other in the thickness direction of the tube, havean opposite-phase relation with each other.